An outdoor shelter and a rail system for the outdoor shelter are disclosed herein. The outdoor shelter includes a plurality of corner support members disposed at respective corners of the outdoor shelter, the plurality of corner support members comprising a first corner support member, a second corner support member, a third corner support member, and a fourth corner support member; a plurality of peripheral beam members, a first one of the plurality of peripheral beam members configured to extend in a longitudinal direction between the first and third corner support members, and a second one of the plurality of peripheral beam members configured to extend in a transverse direction between the first and second corner support members; and a shade member disposed above at least one of the first and second ones of the plurality of peripheral beam members.